Revert "Revert "Migrating all model tests to Instrumentation tests""

This reverts commit 7a4a30d86d.

Test: Presubmit
Reason for revert: Fixing original bug

Bug: 196825541
Change-Id: Id4b1eb24a89564d264266d305aebea52917dfcd9

src/com/android/launcher3/util/SettingsCache.java

@@ -47,7 +47,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
  *
  * Cache will also be updated if a key queried is missing (even if it has no listeners registered).
  */
-public class SettingsCache extends ContentObserver {
+public class SettingsCache extends ContentObserver implements SafeCloseable {
 
     /** Hidden field Settings.Secure.NOTIFICATION_BADGING */
     public static final Uri NOTIFICATION_BADGING_URI =
@@ -69,7 +69,6 @@ public class SettingsCache extends ContentObserver {
     private final Map<Uri, CopyOnWriteArrayList<OnChangeListener>> mListenerMap = new HashMap<>();
     protected final ContentResolver mResolver;
 
-
     /**
      * Singleton instance
      */
@@ -81,6 +80,11 @@ public class SettingsCache extends ContentObserver {
         mResolver = context.getContentResolver();
     }
 
+    @Override
+    public void close() {
+        mResolver.unregisterContentObserver(this);
+    }
+
     @Override
     public void onChange(boolean selfChange, Uri uri) {
         // We use default of 1, but if we're getting an onChange call, can assume a non-default